There has been speculation that the killing at Stithians may have been linked to a Satanic ritual.

Mrs Penn said: "I was led to believe there are cults and they made sacrifices on specific days."

Some internet forums have contained speculation that the most recent killing coincided with St Winebald Day on 7 January, which is said to have been included on Satanic calendars as a date for blood rituals.

A spokesman for Devon and Cornwall police said: "We're keeping an open mind with many lines of inquiry as to what happened. There is nothing specific to suggest that this is the case, there are no facts, it's speculation.

"It was a savage attack on or near a date, but there is nothing to suggest that it is things like a Satanic worship attack."

The RSPCA's spokesperson for the region, Jo Barr, said: "It's impossible to know at the moment what the motivation was behind the attack.

"I have been with the RSPCA for eight years. In my time I am only aware of one incident which was potentially linked.

"There were a couple of attacks on Dartmoor on sheep. There were suggestions that the bodies were left in a formation, I believe it was a pentangle, it was suggested it was linked to Satanic practices or witchcraft."